Anchor escapement

ABSTRACT

An anchor escapement in which the escape wheel intermittently moves over a distance corresponding to the spacing between more than two teeth of a normal escape wheel, this movement being known as a free jump. The escape wheel is a modification of a normal escape wheel having at least 20 teeth, the spacing between at least two of the said teeth being enlarged to provide for the free jump. The number of consecutive teeth between each enlarged space is greater than two and less than seven. The escape wheel is geared to a device for rendering the free chamber visible.

United States Patent 1191 [111 3,805,513 Theurillat Apr. 23, 1974 ANCHOR ESCAPEMENT 3,645,089 3/1972 Yamada 58/28 D [76] Inventor: Xavier The riuat 23 0 L Cha 3,134,220 5/1964 Melsner 58/28 A De Fonds, Switzerland Primary Examiner-Richard B. Wilkinson [22] Fled: 1972 Assistant Examiner-Edith Simmons Jackmon [21] Appl. No.: 312,654 Attorney, Agent, or Firm-Robert E. Burns; Emmanuel J. Lobato [30] Foreign Application Priority Data Dec. 6, 1971 Switzerland 17762/71 [57] ABSTRACT Dec. 6, 1971 Switzerland 17763/71 Dec. 6, 1971 Switzerland 17764/71 escapemem b' the escape F Feb. 25, 1972 Switzerland 1105/72 m moves over a d'stance correspmdmg to May 29 1972 Switzerland 7949 72 the Spacmg between than two teeth a nrmal escape wheel, this movement being known as a free 52 us. Cl 58/116, 58/28 D, 74/115 l'ump- The escape wheel is a "mmal 51 Int. Cl. G041) 15/00, G046 3/04 escape wheel having least, 20 teeth F Spacing [58] Field of Search 58/28 D, 116-117, least the Sam teeth bemg 58 7 4/115 provide for the free ump. The number of consecutive teeth between each enlarged space is greater than two [56] References Cited 3nd less than geven. Tlhefesca ille wllgeel lgleared to a evlce or ren erlngt e ree c am er VlSl e. UNITED STATES PATENTS 1,995,363 3/1935 Rhodes 58/117 7 Claims, 10 Drawing Figures 2-ATENTEDAPR23 mm 18055113 SHEET 1 OF 6 PATENTEUAPRZB I914 3805513 SHEE'I 3 OF 6 FIG.4

1 ANCHOR ESCAPEMENT The present invention relates to an anchor escapement in which the arrangement of the teeth of the escape wheel provides for three jumps of the escape wheel following a certain number of alternations of the balance wheel.

An escapement of this type is known from Swiss Pat. No. 358,036 but since this escapement does not permit a free jump after more than four consecutive alternations of the balance wheel by means of a single escape wheel, the proposed solution is too complicated to be applied.

An object of the present invention is to resolve this difficulty.

. There are described hereafter, as examples and with reference to the accompanying drawings, two embodiments of an escapement according to the invention and various devices employing an escapement of this type.

FIG. 1 is a diagrammatic plan view of the first embodiment of this escapement,

FIG. 2 is a diagrammatic plan view of the second embodiment of this escapement,

FIGS. 3a and 3b are diagrammatic sectional and plan views of a first device,

FIG. 4 is a diagrammatic plan view of the second device,

FIG. 5 is a diagrammatic plan view of a third device,

FIG. 6 is a plan view of a fourth device,

FIG. 7 is a plan view of a fifth device,

FIG. 8a and 8b are plan and side views of a sixth device.

The escapement illustrated in FIG. 1 is particularly intended for a watch whose frequency is 18,000 oscillations per hour. The wheel employed can be regarded as a normal 2l-teeth escape wheel in which three teeth have been suppressed to leave three groups of six teeth, the third and fourth tooth of each group of six being connected to provide a plate 1 with a curved free edge coincident with the outer circumference of the wheel. This plate 1 extends the function of the last tooth before the free jump and suppresses, due to its presence opposite the pallet of the anchor, during the rapid free jump, the possibility of a brief frictional engagement of the point of the fork against the small plate of the balance wheel. With this suppression of friction following any external shocks, the escapement in question retains all the guarantees of good operation of the customary anchor escapement.

As illustrated, the tooth 2 rests against the entering pallet in the rest position at the end of the free jump, and there then follow five half-oscillations of the anchor to give normal operation of the escapement and, after the fifth half-oscillation. the wheel will continue its course in a free jump during which the plate 1 will pass in front of the entering pallet, whereas at theend of this jump, the tooth 2 will rest against theexit pallet. The cycle is then repeated, each of the pallets alternately arresting the wheel at the end of the free jump.

In practice, the good operation of the escapement is which are suppressed, namely one after each group of six consecutive teeth.

The same operation of the escapement is obtained with the following distribution of teeth of the wheel; three groups of three teeth and three groups of two disposed alternately one after the other and separated from each other by a space double that comprised between consecutive teeth forming the groups.

For 21,600 alternations per hour (FIG. 2) the only modification applied to a 20 teeth escape wheel is the suppression of five teeth, namely one after each group of three consecutive teeth.

The wheel is stopped at the end of the free jump by the abutment of the first tooth of the group against the exit pallet. Six normal escapement functions will follow by the alternations of the anchor and the last function will be extended by a free jump of thewheel. At the end of the latter, as at the end of the following free jumps, the wheel will always stop in an identical position to that illustrated in the drawing (FIG. 2), the first teeth of each group of three in turn abutting against the plane of rest of the exit pallet.

The kinematic and dynamic properties of the free jump thus produced may serve for the engagement, disengagement and maintenance of various mechanisms, in particular, these properties may be used to make the beating of the second visible by several devices which will be described.

The first of these devices is illustrated in FIG. 3a and 3b.

In the free inner space at the top of an arbor 31 a tube 32 is freely adjustable, its clearance with regard to height being limited on either side by an internal shoulder of the arbor and the top of a tube 33 fixed in the arbor. Fixed to the projecting end of the tube 32 is a needle 34 for the second beat. Above the latter, a short arm 35 is fixed to the shaft 36 of aseconds wheel, the escapement of which is of the free jump type as described previously, a finger 35 at the end of the arm 35 being located in an aperture provided in the needle 34. Finally a friction member 37 is placed between the top of the minutes needle adjustment 38 and the bottom of the needle 34.

The operation of the device is as follows:

The hand 34 is stopped by the friction member 37 immediately after the free jump. During the six escapement functions which will follow the finger 35 will move in the opening of the needle 34 without any contact therewith. At the end of the sixth function, or at the beginning of the free jump, the finger 35' approaches the opposite wall of the opening; the free jump which follows throws the hand, abruptly so that it moves, under the effect of its weight, until the other edge of the opening abuts against the finger 35' which is stopped at the end of the free jump. At this time, the moving parts are located in the initial position illustrated in drawing. For the period of 1 second the hand 34, will remain stopped under the action of the friction member 37 whereas the finger 35" has continued its course without any contact, thus re-commencing the cycle of operations described.

Further embodiments may be adapted dependent on the features of the movement chosen, for example: If the high ratio wheel is located at the centre of the plate, its arbor will fulfil the function of the tube 33.

The second hand 34 may be journalled in the external extension of the arbor as well as that of the tube 33 or of the shaft of the centre wheel and pinion.

In order to mask the aperture provided in the needle 34 a pivot may be placed under the centre second hand 35 giving this hand the appropriate width. In order to obtain the best functioning of the system, it is necessary that the second beat needle 34 has a certain weight and that it is more or less balanced; in turn the centre second hand 35 will be as long as possible.

A second device will be described with reference to FIG. 4.

On the face, each of the spaces of 6 degrees through which the needle moves in one second, comprises two zones of contrasting colours for example a white zone 41 and a black zone 42 as illustrated in the drawing. The end of the second hand comprises a black surface 43 which in this case corresponds exactly to the total sides of the two zones 41 and 42.

In watches having 18,000 and 21,600 alternations per hour for example it is possible to obtain the instantaneous impression of the second beat, the latter being caused by the so-called free jump escapement previously described.

The variety of applications of this device is very great; the following considerations will indicate the range; the divisions of the second (zones) may appear either on the face or under the glass of the watch; the width and spacing of these divisions may vary as de sired; the indicator member mentioned may be formed either by a hand or by a transparent metal sheet on which will beplaced one or two diametrically opposed surfaces in order to correspond with the type of divisions of the second chosen; or even by a disc of transparent material on which will appear the number of desired surfaces 43 in principle from 1 to 60: assortments of the set of shapes or colours, certain embodiments do not lack originality; for example with the use of a disc having 60 surfaces 43 under a glass where the 60 divisions are marked by varying the colours with the basic shade of the face, the beating of the second is apparent in a most striking manner.

A third device will be described with reference to FIG. 5.

Fixed to the shaft 51 of an escapement wheel having free jumps previously described is a member 52 comprising a number of pins equal to that of the free jumps for one revolution of the wheel, namely five for 21 ,600 alternations per hour. These equi-distant pins 53 cooperate with the six arms 54 of a pivoting member 55 placed at the periphery of the escape wheel. A weak friction or engagement spring (not shown) keeps this member 55 in the stationary position. Finally, fixed to the shaft 56 of the latter is the closure member 57 of the two slots 8 and 9 partially illustrated in dotted line.

The arrows indicate the direction of movement.

The operation is as follows:

The member 55 is stationary for 1 second, held in position by the friction spring; the slot 58 reflects the colour of the 60 sector 57 whereas the other slot 59 reveals another contrasting colour of the sector 57 During this time (1 second), the escape wheel participates freely in six escape functions .without a pin 53 coming into contact with the arms '54 of the member 55. Then the free jump intervenes in the position shown in the drawing; thus the pin 53, already thrown forwards by the last escape function, abruptly comes into contact with the arm 54 to entrain it during the entire movement of the free jump. Under the effect of the force of inertia a member 55 and the closure member 57 will continue their course until the following arm 54' abuts against the same pin 53 when stopped at the end of the free jump.

. Due to this abrupt displacement of the closure member (60) the slot 59 will show the colour of the sector 57 whereas the other slot 58 will receive the colour of the following sector 57", in the main, identical to that of the sector 57'. In turn, during the stoppage for one second of the closure member, the escape wheel will participate in a new series of six functions without a pin 53 coming into contact with an arm 54, in order finally to return to the position of the members in the drawing. The renewal of this cycle thus causes a rapid and precise alternation of the colour in the two slots, thus indicating in an aggreeable manner the beat of the second.

, In addition to the importance of the radical separation of the escape functions and closure functions, this new system has the advantage of facilitating a larger opening of the slots. The practicable margin'between these apertures and the limits of the sector (see drawing) also offers a greater facility for the positioning of the closure member.

For example, by choosing a closure member having five sectors of 72 each, it is possible to obtain quite a large slot facilitating the digital indication of the seconds in parts of l to 5, each sector having in order one of these numbers.

The number of arms 54 of the member 55 is in inverse ratio to the size of the closure sectors.

Instead of being on a member 52, the pins 53 may be located directly in the verge of the escapement wheel.

The support member for the closure member may also be located in coaxial position to the escape wheel. In this case, a single member integral with the escape wheel, located in a notch of appropriate length provided on the member integral with the closure member, causes the periodic entrainment and stoppage of the closure member.

A fourt embodiment is-illustrated in FIG. 6 and relates to a watch having a frequency of 18,000 alternations per hour. The friction spring keeping the seconds wheel 61 in position is not shown whereas this wheel 61 of 60 teeth is partially shown.

The pinions 62 fixed to the shaft 63 of the escape wheel of a free jump escapement previously described bears by one of its sides against one tooth of the seconds wheel 61 whereas the free jump of the escape wheel has already begun. During the course of this jump, the wheel 61 will be abruptly entrained and will pursue its course under the inertia force in order to then be stopped by the abutment of the following tooth against the same side of the pinion 62 on stopping at the end of the free jump. In its course, the seconds wheel 61 will thus have covered exactly one-sixtieth of a revolution, which is equivalent to the beat of the second. Whereas the wheel 61 remains in position due to friction, the pinion 62, entrained by the escape wheel which in turn participates in six escape functions, is nolonger in contact with said wheel 61 due to the very large engagement play. After the escape operation the following free jump occurs, the moving parts 61 and 62 being in an identical position to that illustrated in FIG. 6. Thus, the cycle of operation continues.

If the pinion of the escape wheel comprises six wings, it is understood that the latter may replace the adjusted pinion 62 on condition that the width of the wings is decreased in order to obtain the necessary engagement play.

In the device intended for a watch working with the frequency of 21,600 alternations per hour, the only difference is that the pinion 72 comprises five wings instead of six.

In the case where the given size of the seconds wheel 72 would no longer make it possible to obtain a sufficient width of its teeth, the following embodiments have been provided; they no less guarantee the same qualities of operation.

For 21,600 alternations per hour (FIG. 7) the device comprises, in addition to the customary wheel 71, a pinion 72 freely adjusted on the shaft 73 of thefree jump escape wheel. This pinion 72 is limited in its stroke by a wing part 74 of the escape pinion (or other contiguous member). The position given is at the same stage of the operation as shown in FIG. 6. Since the free jump has begun, the wing 74 entrains the pinion 72 and consequently the wheel 71. In its forwards movement, given the normal width of the teeth and wings, the following tooth of the wheel 71 encounters the wing of the pinion 72 before the end of the journey of said wheel 71, adjourning necessary for the normal beating of the second; but as this pinion 72 is mobile, it offers no resistance before its wing 75 has encountered the wing part 74 of the escape pinion which has stopped at the end of the free jump. This additional journey thus allows the wheel 71, to accomplish its full course without hindrance. The escape wheel then accomplishes its six functions whereas the following wing of the pinion 72 moves closer by one tooth of the wheel 71 and the wing 74 moves away from the wing 75 in order finally to reassume the same position of forwards movement of the wheel 71 immediately after the commencement of the following free jumps.

In the case of 18,000 oscillations per hour, the only change in the system will be a moving pinion 72 having six wings in place of five. It is understood that in the two devices, the number of wings of the escape pinion are unimportant.

Still based on the same-principles, a last embodiment (FIGS. 8a and 8b) is used at 18,000 oscillations per hour.

The seconds wheel has its 60 teeth distributed over two superposed planes 81 (drawn in full line) and 81' (drawn in thin line) alternating the position of each tooth, one above and one below. Fixed to the shaft 83 of the escape wheel are two identical cams 82 (full line) and 82' (thin line) which are staggered by 60. Both these cams cooperate respectively with each of the toothed planes 81 and 81' of the wheel.

The free jump of the escape wheel having already begun, the cam 82 comes into contact with the wheel 81, the latter is thrown forwards abruptly and continues its course solely under the effect of the inertia force in order to be finally stopped, the following tooth (lower 81 abutting against the heel of the cam 82' which has stopped after the end of the free jump. The five escape functions which follow take place without contact be tween the cams and the wheeland the following free jump throws the wheel 81' forwards through the intermediary of the cam 82 then the cycle of operations continues. The seconds beat takes place under the alternating action of each of the cams 82 and 82'.

In all the systems mentioned, the entrainment function of the seconds wheel is ensured by gear wheels, in such a way that a displacement of the seconds hand is no longer possible. Under the effect of a severe external shock, only a slight displacement may be produced, bt the latter remains imperceptible since everything is restored to perfect order in the following second.

What is claimed is:

1. An anchor escapement for clocks and watches comprising an escapement wheel having a plurality of teeth disposed extending outwardly around its periphery and defining spaces therebetween, said teeth being spaced so that at least one of said spaces is circumferentially longer than others of said spaces, and an anchor pivotally mounted to engage individual teeth of said wheel one at a time to allow incremental rotation of said wheel wherein a length of an increment of rotation is directly proportional to a space disposed toward a direction of motion of said wheel next to a tooth engaged at the end of said increments of rotation.

2. In an anchor escapement for clocks andwatches according to claim 1 wherein said escapement wheel has at least 20 teeth and a number of consecutive equispaced teeth greater than two and less than seven spaces between teeth greater than spaces between said equispaced teeth, and indicating means engaging said escapement wheel to render incremental rotations correspondng to said spaces between teeth greater than spaces between said equispaced teeth visible.

3. In an anchor escapement for clocks and watches according to claim 1 wherein said escapement wheel teeth are arranged in equispaced groups, and the spacing between teeth in each group is unequal.

4. In an anchor escapement for clocks and watches according to claim 2 wherein said indicating means comprises a surface having indicia corresponding to increments of time marked thereon.

5. In an anchor escapement for clocks and watches according to claim 2, wherein said indicatingmeans comprises a seconds wheel driven by said escapement said seconds wheel having an entrainment pin integral therewith, an indicator member rotatably mounted and provided with an aperture, said entrainment pin engaging said aperture to rotate said indicator member to render incremental motion of said seconds wheel easily visible.

6. In an anchor escapement for clocks and watches according to claim 2, wherein said indicating means comprises an opening in the face of a clock or watch, and means pivotally mounted engaging said escapement and provided with colored sectors visible through i said opening.

7. In an anchor escapement for clocks and watches according to claim 2 wherein said indicating means comprises a wheel engaging said escapement wheel,

and a seconds indicating member mounted on said wheel in order to indicate passage of seconds by incremental movement developed by said escapement. 

1. An anchor escapement for clocks and watches comprising an escapement wheel having a plurality of teeth disposed extending outwardly around its periphery and defining spaces therebetween, said teeth being spaced so that at least one of said spaces is circumferentially longer than others of said spaces, and an anchor pivotally mounted to engage individual teeth of said wheel one at a time to allow incremental rotation of said wheel wherein a length of an increment of rotation is directly proportional to a space disposed toward a direction of motion of said wheel next to a tooth engaged at the end of said increments of rotation.
 2. In an anchor escapement for clocks and watches according to claim 1 wherein said escapement wheel has at least 20 teeth and a number of consecutive equispaced teeth greater than two and less than seven spaces between teeth greater than spaces between said equispaced teeth, and indicating means engaging said escapement wheel to render incremental rotations correspondng to said spaces between teeth greater than spaces between said equispaced teeth visible.
 3. In an anchor escapement for clocks and watches according to claim 1 wherein said escapement wheel teeth are arranged in equispaced groups, and the spacing between teeth in each group is unequal.
 4. In an anchor escapement for clocks and watches according to claim 2 wherein said indicating means comprises a surface having indicia corresponding to increments of time marked thEreon.
 5. In an anchor escapement for clocks and watches according to claim 2, wherein said indicating means comprises a seconds wheel driven by said escapement said seconds wheel having an entrainment pin integral therewith, an indicator member rotatably mounted and provided with an aperture, said entrainment pin engaging said aperture to rotate said indicator member to render incremental motion of said seconds wheel easily visible.
 6. In an anchor escapement for clocks and watches according to claim 2, wherein said indicating means comprises an opening in the face of a clock or watch, and means pivotally mounted engaging said escapement and provided with colored sectors visible through said opening.
 7. In an anchor escapement for clocks and watches according to claim 2 wherein said indicating means comprises a wheel engaging said escapement wheel, and a seconds indicating member mounted on said wheel in order to indicate passage of seconds by incremental movement developed by said escapement. 